Metal spray gun



Nov. Z1, 1939. 4 .G. L. HAMMON METAL SPRAY GUN Filed Dec. 17, 1934 3 SheetsSheet 1 Nov. 2l, 1939. ca. L, HAMMoN METAL SPRAY GUN Filed D'eo. 17, 1934 3 Sheets-Sheet 2 4INVENTOR. Geoge L. )Kammer-1 ATTORNEY.

-N0v.21,1939. G LHAMMN 2,131,032-

METAL SPRAY GUN Filed Dec. 17, 1954 3 Sheets-Sheet 3 INVENTOR.

Ceci-9@ Jr/emmen.

ATTORNEY.

Patented Nov. 21,1939

vPii'r-ialvr OFFICE METAL SPRAY GUN George L. Hammon, San Francisco, Calif., assign'- or to Nationall Welding Equipment Company;l San 1lranciscoCalii'., a corporation of y(lali- Appucaaon December 17, 1934. serial Nn. '157.876

Claims.

'I'his invention relates to improvements in metal spray gun of the class i which a metal wire is fed through a ilame of intense heat. In this instance the llame of an Oxy-acetylene torch is described but any suitable gas may be used, to

' convert the metal wire into molten metal which is blown againstthe surface to be coatedby the action of compressed air.

Practically any commercial metal may be 0 sprayed on surfaces of aV great variety ofA materiais. The eld for this art is constantly enlarging.

The art itselfbeing old, the present invention relates more particularly to improvements in the burner` tip, the wire feeding means, the controi of the fuel inlets and the air inlet, improved means of assembling the various parts and im,- provements in the body and general arrangement of theparts vfitting therein.

Among the obiectsof the invention means are provided for mounting knurled'feed rollers so that both of the rollers are movable toward and vaway from each other andmeans for moving the rollers to gripthe wire or release it. t

Another object is to providejspring means to force the rollers apart, and automatic means to` f orce the rollers together on the metal wire when a hinged lid is closed and means to adjust the tension of .therollers on the wire. l Another object is to provide shafts for the rollers mounted in' roller bearings and, having driving means to allow fo'r the tilting movement of the shaftswhen bringing separating them.

Another object is to provide an air jet turbine vwheel adapted torun ata very high speed and having suitable reduction gearing to drive the roller shafts, and 'providing means tol discharge the exhaust air through the hollow handle of the gun to act as a silencer for the exhaust air, and

also to keep the gun cool for the hand of the operator.

Another-object 'of the inventionis to providean air jet on the handle or other suitable loca--n -tion on the gun to `*receive compressed airl and direct it to a respirator worn by operator of the gun by means of a hose connection thussupply- `ing fresh air and free from the spray to the operator. The air -Another object is the provision of the gas and acetylene inlet Vis opened rst, the oxygen second and the Air last,

the rollers together or may be taken direct from the- (ci. en -12.2) i

A 4further objectl of the invention is'the coinbination of' a. mixing chamber to automatically mix .the gases as they ilow'to the burner tip, and to provide a mixer that is easily removed from the' body of the gun from the outside. vAnother object isto provide an air inlet'jet member to the turbine having a removable tip,

and one in which the air can be regulated, and

also'one that can be removed from the outside of the gun body. The air jet to have 'a direct air connection to the source of supply.

Another object is to provide feed rollers that are reversible so, thatwhen one surface. of the knurled portion is worn smooth a new surface is exposed when reversed. Other objects of the invention will appear to those skilled in 'this art a's the description progresses.`

An embodiment of the vinvention isy shown in he accompanying drawings in which the same reference numeral is applied tothe same portion throughout the several views of which there may a Vbe modifications. ,f

Figure 1 is a sectional' view of the gun, a projecting portion o1' the burner being broken away.

r, Figure 2 is a viewJ of the burner and shows the part broken away in Figure 1.

Figure is a top view of the gun, the cover being removed.

Figure 4 is a side view of the spray gun partly in section.

Figure 5 is a section on line 5-.5 of lFigure 4. Figure 6 is a detached view showing the operat ion of the control lever on the inlet va1ves.

Figure 1a is a section on line Ia-Ia of Figure 1 toshow thehexagon shape of the stem on the adapter. Figure 'l is a view from below showingA the arrangement of the gas and air tubes. a Figure 8 is a`sectional -view showing the wire driving mechanism. I 1 Figure 9 is a view looking from the bottom to show how the bearings andvertical shafts are moved toward, or -away from each other.

Figure 10 is a view of the rollers andspreading means, the cover being removed. Figure 11 is a section showing a portion 'of the cover, andthe rollers and moving means, and also thetension device.

Figure 12 is a sectional view showing the operation of the air turbine, the air Jet, andthe exhaust passage. Figure 13 is an edge view of the one piece turbine wheel.

one of the by the partition 1.

In the upper compartment the metal wire feeding means is mounted and arranged to feed the wire at the desired speed to the burner and through the flame where it is melted and blown in a ne mist of metal on the surface to be coated.

The improvements in the burner comprise means to adapt it to metal spraying. There is a boss on the body member as shown at 8, and it has an opening into the chamber 5 into which the stem 8 of a taper adapter member I8 is secured by the threaded nut I I. There is an opening I2 for the passage of the wire, and an annular groove I3 in the taper member which is in alignment with an annular groove I4 in the boss. There is also a distributing chamber I3 between the taper portions I1 and I8', and communicating ports I4 between the 'two chambers. On the taper adapter member is a threaded portion I5 and a threaded cap I5 acts to secure the burner tip I1 with its central opening I8 in line with the opening I2. Surrounding the central opening I8 there is a plurality of small holes I8 for the fuel mixture from the grooves I3v and I4. In the tip end of the opening I8 there is a small bushing I8 of very hard material to withstand the wear better. The cap I6 has a flange 28 that is approximately the same diameteras the boss '8, and it has a plurality of holes 2l for more evenly spreading the compressed air around the burner inside the cap 22 which is threaded on the outside of the boss. A screen of suitable mesh may be used in place of the holes 2 I.

On the end of the shell there is a tip 23 having a taper fitting the taper of the end of the burner. and in the burner taper there is a plurality of grooves 24. On the opposite side of the body v there is a bell shaped wire guide 25 with its central opening 25 in alignment with the opening through the burner. The bell shaped member having a threaded portion 21 adapted to .screw into the body. The tube 28 being provided to guide the wire close to the feeding'discs, and it has a threaded end portion adapted to thread into Athe body.

A hinged cover 28' has the pivot screws 28, and it is held in the closed position by the catch 38 mounted on the spring member 3| by mets and which is held in place by the bell shaped guide 25. A thin strip of metal 321 is secured to the cover and projects to engage the catch.

The fuel and air under pressure is fed to the burner tubes through the ,hollow handle 2 and are conveyed by ports to the burner.

The acetylene gas tube 33 connects to the port 34 which leads to the mixer. The tube 35 connects to the port 35 and to the mixer, and the tube 31 connects to the port 38 which leads to the outer shell surrounding the burner. Each of the ports 34, 35, and 38 are controlled by a valve 38 having stems 48, 4I, and 42. The valves act to close the ports by means of the spring 38' and when raised allow the passage of the gases and air.

A handle lever 43 is pivoted at 44, and projectng from the lever are the forked members 45 which engage the stems, the stems having threaded .ends on which are threaded nuts 46 and lock nuts 41, the nuts being so adjusted that when the lever is pressed the stem48 moves rst thus allowing acetylene gas to enter the port 34, next the stem 4I is moved allowing oxygen to enter the port 35 and the last stem 42 opens the port 38 to allow air to enter to the burner. Suitable valves 48 are provided for each of the tubes, and exible tubing to connect the gun to the Source of supply. Each of the stems 48, 4I, and

42 have a valve body 48. The lever 43 has the curved end 58 adapted to be engaged by the catch 5I pivoted at 52, and having a spring 53 so when the lever is pressed against the handle the catch will snap over the end and hold the lever and all the valves open thus relieving the operator from constantly holding it down.

'I'he gas mixer utilizes some of the principles shown in my Patent No. 1,818,949,` Mixer lfor welding torches adapted to its usein a metal spray gun. The housing 54 is a part of the body of the gun,v and opens from the outside so the mixer may be removed by taking oil! a screw plug 55. The body, 55, of the mixer has the threads 51 engaging threads in the wall of the opening 58. There is an annular groove 58 in the opening and body of the mixer to which the acetylene port 34 is connected. A cap 58 has a threaded portion 5I which screws into threads in the body 55. 'I'he cap has the closed end 82, and is screwed downl to the shoulder 53. A plurality of small holes'54 are drilled from the outside to the opening 55 in the cap. The interior of the cap'forms the distributing chamber 85. There are by-passes 61 which connect the grooves 58 to the longitudinal bores 58.

A port 88 carries the mixed fuel to the grooves I3 and I4 of the burner.

A turbine wheel 18 is mounted in the recess 1I on the shaft I2 and the ball bearings 13 and 14 on which the shaft is carried are supportedin the openings 15 and 15. Caps 11 and 18 having screw threads close the openings after the shaft is assembled. The shaft may be removed by taking oil the caps, then removing the ball bearing I4 whereupon the turbine and ball bearing .'3 may be removed together.

A worm 'I8 preferably integral with the shaft 12 fs in mesh with the worm gear 88 xed on the shaft 8|, and this shaft is mounted on the ball bearings 82 and 83 supported in openings in the bosses 84 and 85. I'hreaded caps 85-and` 81 retain the bearings in place. By removing the caps and ball bearing 82 the shaft and ball bearing 83 may be removed together. On the shaft 8| are the right and left worms 88 and 88, the worms, the worm wheel 88. and the shaft 8l are made preferably integral, but may be separate parts keyed or otherwise fixed' together. In mesh with the worms 88 and 88 are worin wheels 88 and 8I fixed on the vertical shafts 82 and 83 mounted on the rocking ball bearings 85 and 81. The rocking ball .bearings may be any suitable ball bearing that allows for a slight rocking movement. v

The slidable ball bearings each comprise a ball bearing forced into a ring 88f'having at sides 88 |83 in the partition 'I allow for the rocking movement of the shafts, and these openings are pro-` vided with suitable packing that um :or

the movement of the shafts.

The means for moving the ball and;4

shai'ts consist of pins |l4 and Il! xed in the' rings ,3l on which pivot the levers lli and |31 which levers are pivoted on the boss by the pins |33 and |03. The levers are bent oi! from the center line between the shafts, the endsV thereof vided for this pin.

The pin is operated by the closing ofthe cover which carries a pin ||2 under the adjustable tension of aspring ||3 which rests on a shoulder ||4 and reacts against a hollow nut ||5 which has screw threads in the cover and boss |16. A lock'nut ||1 holds the nut in the adjusted position. The action of the wedge pin forces the levers apart and brings the shafts toward each other, and a spring ||8 holds them apart, and the action of the levers forcel up the wedge shaped pin.\l

Mounted on the shafts are knurled wire feed rollers H3 and |20 adapted to grip the wire at an adjustable tension and cause it to travel toward the burner.-

In the modied form ofthe means to. move the knurled rollers to act on the wire shown in Figures 14 and 15 the ball bearings |33 and |34 are held rigidly in lever members and |36V which are pivoted at |31 and |38 to the gun body,

' andthe end portion of -the levers |39 and |40 are brought close together so that the wedge member III may act to spread them apart and thusbring the rollerstogether on the wire, the

pin |4| being acted on by the cover having an adjustable tension spring and pin or other suitable meansl 'A spring |42 acts to move the rollers apart.

The rollers IIS and |20 are preferably made reversible as shown in Figure 16 so that the wire that is being fed in comes in contact with thelower portion of the knurled surface of the rollers and -when this surface becomes worn the rollers are removed and turned over so that a new surface is used thus getting double wear out. of the rollers.

The turbine is driven from an air jet chamber and comprises a removable tip -|2| which has a threaded portion |22 which engages a threaded opening inthe` body member and a seat for the valve portion of the stem |23, the stem isturned by the knurled wheel |24.

There is aY threaded plug |25 screwed in the opening |26 leaving anair receiving chamber betweenthe plug and tip. A- packing gland |21. Threads |28 on the valve stem engage threads inv the plug |25.

The valve portion of the jet control and. the valves 48 are shown'in my Patent No. 1,944,428 issued January 23, 1934.

A port |29`conne'ctsthe jet` chamber with the air tube 31 and is independent of the, air connection to the burner.

The turbine 1| has the undercutpockets |30 and is made in one piece. An air jet 13| has screw threads in an opening 'in the handle to throw a jet of air through a tube to a respirator ."`worn on the face of the operator from'the exhaast of the turbine, it can be shut' off by tuming it around, or a suitable valve may bepro-r vided.

In operation the cover is opened allowing theV arenoso Plying the art of metal spraying;

knurled rollers to wire is inserted through the guiding tubes tol Athe burner tip. -Now the gas supply and air pressure is turned on to the gun bythe valves ,thentheairpressureisturnedonto the scparate, the end of a metal air jet by the knurled wheel |24 which admits ail' directly from the tube 31 through port |29, after the turbine is brought t0 the required Speed the valve stem |23 is locked in position. If a respirator is t'o be used by theoperator the tube 3 is turned on and the respirator adjusted to the face of 'the'operaton the tlexiblejtube |3|' being in place., at this point the hand lever 43`is in, thus admitting in proper ,sequence the gases in-this instance acetylene gas first, oxygen next.- and then air to the burner from the tube 31, port 38. The acetylene and oxygen going through ports 34 and 36 respectively to the mixer, and from there through the portilto the distributing chamber and from there to the burner tip inside air cap 22, the gases are now ignited and the cover closed which brings the knurledfeed rollers together to im- A,pinge the wire which is ,carried through the burner and turned into molten metal and blown It will be seen from the above description taken with the drawings that a very complete and eillcient means have been provided in ap- VAHaving thus described my invention wish to secure by Letters Patent' of the United States is as follows, but modications may be had in carrying out the invention as shown vin the accompanying drawings and the particularly described form thereof within the purview of the annexed claims. Y,

I claim:

1. A metal spray guny of the class described comprising a body, a burner, a pair of movably mountedfeedrollers adapted to feed a wire toV said burner, means to drive'saidv feed rollers, means to move both of said rollers towards each other to grip the wire, and to move 'said rollers awayfrom each other to release the wire.

2. A metal spray gun of the class described comprising a gun body, a metal melting burner for said gun body, ya pair of movably mountedl feed rollers adapted to feed a metal wire to said.

burner, means to drive both ofsid rollers, means 'to move both of said rollers towards each other to grip the wire, means to adjust theV tension of said gripping means, means to move said rollers away from'each other toY release said Wire.

3. A metal spray gun of the class described comprising a gun body, a handle for said body, a m'etal melting burner for said body, a pair of metal wire feed rollers movably mounted adapted ,to feed a wire to said burner, vmeans to move both of said rollers simultaneously to grip orrelease said wire.

4. A metal spray gun of the class described comprising a gun body havingtwo compartments, means to guide and feed a metal wire in one of the compartments, and means to drive -with fuel and Vcompressed air through the handle,

what' I 'the feeding means in the other compartment, a. Vburner projecting from saidhody, a hollow han'- dle for said body, m'eans to supply the burner and compressed air to the driving means through said handle, and means to exhaust compressed Yair through said handle to cool the handle, and

direct the exhaust downwardly below the operators hand.

5. A metal spray gun of the class described comprising a body member, a burner for said body, means to guide a wire to said burner, a feed roller on each side of the path of said wire, vertical shafts for said rollers, ball bearings for the upper part of said shafts, means to mount said bearings slidable to move toward or away from each other, ball bearings for the lower portion of said shafts, means to provide a rocking motion for said bearings, adjustable means to move the upper bearings on said `shaft whereby said rollers may grip said wires, and spring means to separate said rollers.

6. A metal spray gun of the class described comprising a body member, a burner for said body, an opening through said burner to admit a metal wire, guiding means for said Wire, a pair of opposed rollers adapted to grip and propel said wire throughA the burner opening, fuel passages from a source of supply to said burner, a mixer interposed in said passages, a shaft for each of said rollers, driving gear for said shafts,

vmeans to'move said shafts towards and away to release said wire.

7. A metal spray gun of the .class described comprisinga hollow body member having two compartments upper and lower, wire guiding and propelling means in the upper compartment, driving means for said propelling means in the lower compartment, a burner having an opening therethrough for said wire, fuel passages from a source of supply to a mixer, said mixer mounted in a housing having an opening from the side of said body, a mixer body member having threads adapted to screw into said opening, distributing and mixing chambers connected by longitudinal bores with by-passes leading therefrom, a further distributing chamber at the end of said mixer body, ahollow. cap in said chamber having radial perforations, a supply tube connected to said chamber, a supply tube connected tosaid by-passes, and means to admit the different fuel in predetermined sequence.

8. A metal spray gun of the class describedcomprising a body member, a burner having an opening therethrough for a wire, guiding means for said'wire, feed rollers for said wire, vertical shafts for said rollers, means to move both of said shafts to grip or release said wire. worm wheels on said shafts, a cross shaft having bearings in said gun body, a right hand worm for one of said worm wheels, and left hand worm for the other of said worm wheels on said cross shaft,

A a worm wheel on said cross shaft, a drive shaft having a vworin in mesh with the worm wheel on said cross shaft, an air turbine wheel on said drive shaft, an air inlet jet for said wheel, a threaded removable tip for said jet, an adjustable valve for said jet adapted to seat in said tip, a hollow handle open at its lower end for said gun body, and a passage way from said turbine to said hollow handle whereby the exhaust from said turbine is discharged through said handle.

9. A metal spray gun of the class described comprising a body member, a burner having a tip with a central opening, a plurality of longitudinal openings surrounding said central opening from the inner end to the outer end, a plurality of grooves on the outer end, taper surfaces on the inner end adapted to engage taper seats, a base member having taper seats adapted to receive the taper portions of said tip member,l

an outer cap member fitting over the end of of said tip, communicating ports and distributing chambers from a fuel supply to said longitudinal openings, and a communicating port and a distributing chamber from an air supply to the passages formed by the grooves in the taper surface and the outer cap.

10. A metal spray gun of the class described comprising a body member, a burner having a tip in one piece, a central opening through said tip, one end of said tip having a taper portion spaced from the end and a smaller taper portion on a reduced portion of the tip, the other end of said tip having a taper end with longitudinal grooves therein, a bushing of harder material in the central opening in the discharge end of said tip, longitudinal openings surrounding said central opening, an adapter memberhaving a taper surface engaging a taper receiving .surface in said gun body, a threaded stem on said adapter having a threaded nut to hold it in place, a threaded portion on said adapter, a threaded cap engaging said threaded portion, a shoulder on said tip adapted to be engaged by said cap, and an outer cap enclosing said tip, communicating ports and distributing chambers from a fuel supply to said longitudinal openings, 'and a communicating port and a distributing chamber from an air supply to the passages formed by the grooves in the taper surface and the outer cap.

11. A metal spray gun of the class described comprising a body `member, a burner on said bodyfmeans to supply gas to said burner, a pair of movable knurled rollers adapted to feed a metal wire to said burner, said rollers being mounted so that in one position the wi're ls contacted by certain portions of the rollers, and

said rollers being adapted to be reversed in posi-- tion. to bring the wire in contact with other surfaces of said rollers whereby additional wearing surfaces are provided for the rollers.

1'2. A metal spray gun of the class described comprising a body member, a burner on said body, means to supply suitable gas and air under pressure to said burner to produce a melting iiame, a pair of movable rollers adapted to fric- 'tionally engage a metal wire, means to move both of said rollers simultaneously to release or engage said wire, and means to adjust the tension of the rollers on said wire.

13, A metal spray gun of the class described comprising a body member, a burner on said body, a pair of opposed rollers adapted to impinge a wire and feed it to said burner, a movable shaft for each of said rollers, upper and lower bearings for said shafts, a lever adapted to carry each of said upper bearings, pivots for said levers on said body, adjustable tension means acting on said levers tobring said rollers together, and a spring to separate them, and means to drive said shafts.

14. A metal spray gun of the class described comprising a body member, a taper recess in said body, a hexagon opening leading from said recess into said body, an adapter having a stem to fit said opening, screw threads on said stem. a nut engaging said threads on the inside of said body, a distributing chamber formed between said recess and the body of the adapter, a communicating port from a source of mixed gases to said chamber, spaced recesses in said adapter having taper surfaces, a one piece tip member having taper surfaces to nt said last mentioned recesses, a distributing chamber, a plurality of longitudinal openings through said tip communicating withlsaid second distributing chamber,V ports connecting ,said distributing 15. In an apparatus ofthe character described, a pair of rocker arms,.a -bearing at one end oi' each rocker arm, a vertical shaft journaled in each bearing, a wire feedingwheel secured on each shaft, means engageable with the opposite ends of the rocker arms whereby movement is imparted to bring the wire feeding wheels towards each other to-grip a wire, and means for driving the vertical shafts and the wire feeding wheels secured thereto in unison.

GEORGE L. HAMMON. 

